Suction cup



FIG. 1 is a perspective view for a suction cup of my new design;

FIG. 2 is a right elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left elevational view thereof; and,

FIG. 7 is a rear elevational view thereof. 

The ornamental design for a suction cup, as shown and described. 